Carl Zimmer writes: Over the past few million years, the ancestors of modern humans became dramatically different from other primates. Our forebears began walking upright, and they lost much of their body hair; they gained precision-grip fingers and developed gigantic brains.
But early humans also may have evolved a less obvious but equally important advantage: a peculiar sleep pattern. “It’s really weird, compared to other primates,” said Dr. David R. Samson, a senior research scientist at Duke University.
In the journal Evolutionary Anthropology, Dr. Samson and Dr. Charles L. Nunn, an evolutionary biologist at Duke, reported that human sleep is exceptionally short and deep, a pattern that may have helped give rise to our powerful minds. [Continue reading…]
Category Archives: Anthropology
6,000 years ago humans upturned 300 million years of evolution
Smithsonian.com reports: It’s hard to imagine a global force strong enough to change natural patterns that have persisted on Earth for more than 300 million years, but a new study shows that human beings have been doing exactly that for about 6,000 years.
The increase in human activity, perhaps tied to population growth and the spread of agriculture, seems to have upended the way plants and animals distribute themselves across the land, so that species today are far more segregated than they’ve been at any other time.
That’s the conclusion of a study appearing this week in the journal Nature, and the ramifications could be huge, heralding a new stage in global evolution as dramatic as the shift from single-celled microbes to complex organisms.
A team of researchers led by S. Kathleen Lyons, a paleobiologist at the Evolution of Terrestrial Ecosystems (ETE) program in the Smithsonian’s National Museum of Natural History, examined the distribution of plants and animals across landscapes in the present and back through the fossil record in search of patterns.
Mostly they found randomness, but throughout time, there was always a small subset of plants and animals that showed up in relationship to one another more often than can be attributed to chance. That relationship either meant that pairs of species occur together, so when you find one, you usually find the other. Or it meant the opposite: when you find one, the other is usually not present, in which case they’re considered segregated. [Continue reading…]
Possessed by a mask
Sandra Newman writes: It is an acknowledged fact of modern life that the internet brings out the worst in people. Otherwise law-abiding citizens pilfer films and music. Eminent authors create ‘sock puppets’ to anonymously praise their own work and denigrate that of rivals. Teenagers use the internet for bullying; even more disturbingly, grown-ups bully strangers with obsessive zeal, sometimes even driving them from their homes with repeated murder threats. Porn thrives, and takes on increasingly bizarre and often disturbing forms.
Commentators seem at a loss to satisfactorily account for this surge in antisocial tendencies. Sometimes it’s blamed on a few sociopathic individuals – but the offenders include people who are impeccably decent in their offline lives. The anonymity of online life is another explanation commonly given – but these behaviours persist even when the identities of users are easily discovered, and when their real names appear directly above offensive statements. It almost seems to be a contagion issuing from the technology itself, or at least strong evidence that computers are alienating us from our humanity. But we might have a better chance of understanding internet hooliganism if we looked at another form of concealment that isn’t true concealment, but that nonetheless has historically lured people into behaving in ways that are alien to their normal selves: the mask.
There doesn’t seem to be any culture in which masks have not been used. From the Australian outback to the Arctic, from Mesolithic Africa to the United States of the 21st century, people have always made and employed masks in ways that are seemingly various and yet have an underlying commonality. Their earliest appearance is in religious ritual. [Continue reading…]
When languages die, we lose a part of who we are
By Anouschka Foltz, Bangor University
The 2015 Paris Climate Conference (COP21) is in full gear and climate change is again on everyone’s mind. It conjures up images of melting glaciers, rising sea levels, droughts, flooding, threatened habitats, endangered species, and displaced people. We know it threatens biodiversity, but what about linguistic diversity?
Humans are the only species on the planet whose communication system exhibits enormous diversity. And linguistic diversity is crucial for understanding our capacity for language. An increase in climate-change related natural disasters may affect linguistic diversity. A good example is Vanuatu, an island state in the Pacific, with quite a dramatic recent rise in sea levels.
There are over 7,000 languages spoken in the world today. These languages exhibit enormous diversity, from the number of distinctive sounds (there are languages with as few as 11 different sounds and as many as 118) to the vast range of possible word orders, structures and concepts that languages use to convey meaning. Every absolute that linguists have posited has been challenged, and linguists are busy debating if there is anything at all that is common to all languages in the world or anything at all that does not exist in the languages of the world. Sign languages show us that languages do not even need to be spoken. This diversity is evidence of the enormous flexibility and plasticity of the human brain and its capacity for communication.
Studying diverse languages gives us invaluable insights into human cognition. But language diversity is at risk. Languages are dying every year. Often a language’s death is recorded when the last known speaker dies, and about 35% of languages in the world are currently losing speakers or are more seriously endangered. Most of these have never been recorded and so would be lost forever. Linguists estimate that about 50% of the languages spoken today will disappear in the next 100 years. Some even argue that up to 90% of today’s languages will have disappeared by 2115.
Millet: The missing piece in the puzzle of prehistoric humans’ transition from hunter-gatherers to farmers
New research shows a cereal familiar today as birdseed was carried across Eurasia by ancient shepherds and herders laying the foundation, in combination with the new crops they encountered, of ‘multi-crop’ agriculture and the rise of settled societies. Archaeologists say ‘forgotten’ millet has a role to play in modern crop diversity and today’s food security debate.
The domestication of the small-seeded cereal millet in North China around 10,000 years ago created the perfect crop to bridge the gap between nomadic hunter-gathering and organised agriculture in Neolithic Eurasia, and may offer solutions to modern food security, according to new research.
Now a forgotten crop in the West, this hardy grain – familiar in the west today as birdseed – was ideal for ancient shepherds and herders, who carried it right across Eurasia, where it was mixed with crops such as wheat and barley. This gave rise to ‘multi-cropping’, which in turn sowed the seeds of complex urban societies, say archaeologists.
A team from the UK, USA and China has traced the spread of the domesticated grain from North China and Inner Mongolia into Europe through a “hilly corridor” along the foothills of Eurasia. Millet favours uphill locations, doesn’t require much water, and has a short growing season: it can be harvested 45 days after planting, compared with 100 days for rice, allowing a very mobile form of cultivation.
Nomadic tribes were able to combine growing crops of millet with hunting and foraging as they travelled across the continent between 2500 and 1600 BC. Millet was eventually mixed with other crops in emerging populations to create ‘multi-crop’ diversity, which extended growing seasons and provided our ancient ancestors with food security.
The need to manage different crops in different locations, and the water resources required, depended upon elaborate social contracts and the rise of more settled, stratified communities and eventually complex ‘urban’ human societies.
Researchers say we need to learn from the earliest farmers when thinking about feeding today’s populations, and millet may have a role to play in protecting against modern crop failure and famine.
Evidence that first toolmakers predated the genus Homo
Discover reports: Thanks to a wrong turn, a stroke of luck and keen eyes, husband and wife research partners Sonia Harmand and Jason Lewis of Stony Brook University could rewrite our understanding of tool use among hominins. With their team from the West Turkana Archaeological Project, the pair have found evidence that a species predating the genus Homo may have made the first stone tools.
In July 2011, Harmand and Lewis and their colleagues were scouting for sites in the area around northern Kenya’s Lake Turkana. There are no roads in this remote region, so Harmand was forced to drive in dry creek beds while Lewis navigated with a GPS device. It’s all too easy to become disoriented in this kind of terrain; at a certain juncture where the GPS indicated a right turn, she mistakenly went left. They soon found the way blocked by bushes. Unable to drive farther, they climbed a small hill to get their bearings. From the top of the rise, the team gazed down on what Harmand describes as a uniquely beautiful landscape.
“I felt certain it contained hidden areas waiting to be explored,” she says. Everyone fanned out to investigate. “We were only 10 people, working far from each other with walkie-talkies. Around 9 in the morning, we had a call from our local Turkana team member, Sammy Lokorodi. He said, ‘You should come where I am because I think I’ve spotted something very interesting.’ ”
He found stone tools sticking out of an eroding creek bed. The surface above had a dark, weathered patina, but the areas around the rocks were light, suggesting they had been only recently exposed. Harmand knew at once this was an important find because the layers in which the tools were embedded were dated to more than 2.7 million years old.
Paleomagnetic dating — matching magnetic properties in the sediments surrounding a fossil or artifact to ancient reversals in the Earth’s magnetic poles to determine age — later determined the tools had to have been made 3.3 million years ago. Despite the tools’ simple form and huge size, some almost 8 inches across, the angle and patterns on the rocks’ edges showed repetitive strikes that could not have resulted from erosion or other natural processes. Publishing the discovery in Nature in May, Harmand and Lewis dubbed the assemblage the Lomekwi 3, after the area where the tools were found. [Continue reading…]
DNA evidence reveals that the people who civilized Europe were migrants
The New York Times reports: Before the rise of agriculture, Europe was home to a population of hunter-gatherers. Then a wave of people arrived whose DNA resembles that of people in the Near East. It’s likely that they brought agriculture with them.
Finally, about 4,500 years ago, a nomadic population from the steppes of Russia, known as the Yamnaya, swept into Europe.
The analyses that revealed these migrations were based on dozens of ancient European genomes. But in a study published Monday in Nature, David Reich, a geneticist at Harvard Medical School, and his colleagues analyzed the genomes of 230 people who lived between 8,500 and 2,300 years ago.
The enormous sample size has provided enough data to track individual genetic variations as they become more or less common through the history of ancient Europe.
The remains that Dr. Reich and his colleagues analyzed DNA from span the entire continent of Europe. They also include the Yamnaya as well as 21 people who lived in a region of Turkey called Anatolia 8,500 years ago. The study marks the first time scientists have been able to analyze the DNA of the people who brought farming to Europe. [Continue reading…]
How the Western diet has derailed our evolution
Moises Velesquez-Manoff writes: For the microbiologist Justin Sonnenburg, that career-defining moment — the discovery that changed the trajectory of his research, inspiring him to study how diet and native microbes shape our risk for disease — came from a village in the African hinterlands.
A group of Italian microbiologists had compared the intestinal microbes of young villagers in Burkina Faso with those of children in Florence, Italy. The villagers, who subsisted on a diet of mostly millet and sorghum, harbored far more microbial diversity than the Florentines, who ate a variant of the refined, Western diet. Where the Florentine microbial community was adapted to protein, fats, and simple sugars, the Burkina Faso microbiome was oriented toward degrading the complex plant carbohydrates we call fiber.
Scientists suspect our intestinal community of microbes, the human microbiota, calibrates our immune and metabolic function, and that its corruption or depletion can increase the risk of chronic diseases, ranging from asthma to obesity. One might think that if we coevolved with our microbes, they’d be more or less the same in healthy humans everywhere. But that’s not what the scientists observed. [Continue reading…]
Why we think the very first farmers were small groups with property rights
For 95% of the history of modern humans we were exclusively hunter gatherers. Then suddenly about 12,000 years ago, something happened that revolutionised the way humans lived and enabled the complex societies we have today: farming.
But what triggered this revolution? Understanding this is incredibly challenging – because this occurred so far in the past, there are many factors to consider. However, by simulating the past using a complex computational model, we found that the switch from foraging to farming most likely began with very small groups of people that were using the concept of property rights.
Farming: an unlikely choice
It may seem obvious why we switched from foraging to farming: it made it possible to stay in one place, feed larger populations, have greater food security and build increasingly complex societies, political structures, economies and technologies. However, these advantages took time to develop and our early farmer ancestors would not have seen these coming.
Indeed, archaeological research suggests that when farming began it was not a particularly attractive lifestyle. It involved more work, a decrease in the quality of nutrition and health, an increase in disease and infection, and greater challenges in defending resources. For a hunter-gatherer at the cusp of the “agricultural revolution”, a switch to farming wasn’t the obvious choice.
In a society where everyone is ready to defend the common good, corruption doesn’t pay
Suzanne Sadedin writes: By making a few alterations to the composition of the justice system, corrupt societies could be made to transition to a state called ‘righteousness’. In righteous societies, police were not a separate, elite order. They were everybody. When virtually all of society stood ready to defend the common good, corruption didn’t pay.
Among honeybees and several ant species, this seems to be the status quo: all the workers police one another, making corruption an unappealing choice. In fact, the study showed that even if power inequalities later re-appeared, corruption would not return. The righteous community was extraordinarily stable.
Not all societies could make the transition. But those that did would reap the benefits of true, lasting harmony. An early tribe that made the transition to righteousness might out-compete more corrupt rivals, allowing righteousness to spread throughout the species. Such tribal selection is uncommon among animals other than eusocial insects, but many researchers think it could have played a role in human evolution. Hunter-gatherer societies commonly tend toward egalitarianism, with social norms enforced by the whole group rather than any specially empowered individuals. [Continue reading…]
Sino-Tibetan populations shed light on human cooperation
One of the big questions in anthropology is why humans, unlike most animals, cooperate with those we are not closely related to. Exactly what has driven this behaviour is not well understood. Anthropologists suspect it could be down to the fact that women have usually left their homes after marriage to go and live with their husband’s family. This creates links between distant families, which may explain our tendency to cooperate beyond our own households.
Now our study on the Tibetan borderlands of China, published in Nature Communications, shows that it is indeed the case that cooperation is greater in populations where females disperse for marriage.
A natural experiment in social structure
There are a lot of different theories about the link between dispersal, kinship and cooperation, which is what we wanted to test. Anthropologists believe that dispersal leads to cooperation through links between families, and some evolutionary models predict that when nobody moves this leads to residents competing for the same resources and greater conflict between kin. But there are also models that suggest the opposite is true – that if nobody moves, neighbours are more likely to be related, leading to more cooperation in the neighbourhood.
Long before going to Europe, humans ventured east to Asia
LiveScience reports: Teeth from a cave in China suggest that modern humans lived in Asia much earlier than previously thought, and tens of thousands of years before they reached Europe, researchers say.
This discovery yields new information about the dispersal of modern humans from Africa to the rest of the world, and could shed light on how modern humans and Neanderthals interacted, the scientists added.
Modern humans first originated about 200,000 years ago in Africa. When and how the modern human lineage dispersed from Africa has long been controversial.
Previous research suggested the exodus from Africa began between 70,000 and 40,000 years ago. However, recent research hinted that modern humans might have begun their march across the globe as early as 130,000 years ago. [Continue reading…]
Humans are natural polymaths, at our best when we turn our minds to many things
Robert Twigger writes: I travelled with Bedouin in the Western Desert of Egypt. When we got a puncture, they used tape and an old inner tube to suck air from three tyres to inflate a fourth. It was the cook who suggested the idea; maybe he was used to making food designed for a few go further. Far from expressing shame at having no pump, they told me that carrying too many tools is the sign of a weak man; it makes him lazy. The real master has no tools at all, only a limitless capacity to improvise with what is to hand. The more fields of knowledge you cover, the greater your resources for improvisation.
We hear the descriptive words psychopath and sociopath all the time, but here’s a new one: monopath. It means a person with a narrow mind, a one-track brain, a bore, a super-specialist, an expert with no other interests — in other words, the role-model of choice in the Western world. You think I jest? In June, I was invited on the Today programme on BBC Radio 4 to say a few words on the river Nile, because I had a new book about it. The producer called me ‘Dr Twigger’ several times. I was flattered, but I also felt a sense of panic. I have never sought or held a PhD. After the third ‘Dr’, I gently put the producer right. And of course, it was fine — he didn’t especially want me to be a doctor. The culture did. My Nile book was necessarily the work of a generalist. But the radio needs credible guests. It needs an expert — otherwise why would anyone listen?
The monopathic model derives some of its credibility from its success in business. In the late 18th century, Adam Smith (himself an early polymath who wrote not only on economics but also philosophy, astronomy, literature and law) noted that the division of labour was the engine of capitalism. His famous example was the way in which pin-making could be broken down into its component parts, greatly increasing the overall efficiency of the production process. But Smith also observed that ‘mental mutilation’ followed the too-strict division of labour. Or as Alexis de Tocqueville wrote: ‘Nothing tends to materialise man, and to deprive his work of the faintest trace of mind, more than extreme division of labour.’ [Continue reading…]
As human power keeps growing, our ability to harm or benefit other animals grows with it
Yuval Noah Harari writes: This is the basic lesson of evolutionary psychology: a need shaped thousands of generations ago continues to be felt subjectively even if it is no longer necessary for survival and reproduction in the present. Tragically, the agricultural revolution gave humans the power to ensure the survival and reproduction of domesticated animals while ignoring their subjective needs. In consequence, domesticated animals are collectively the most successful animals in the world, and at the same time they are individually the most miserable animals that have ever existed.
The situation has only worsened over the last few centuries, during which time traditional agriculture gave way to industrial farming. In traditional societies such as ancient Egypt, the Roman empire or medieval China, humans had a very partial understanding of biochemistry, genetics, zoology and epidemiology. Consequently, their manipulative powers were limited. In medieval villages, chickens ran free between the houses, pecked seeds and worms from the garbage heap, and built nests in the barn. If an ambitious peasant tried to lock 1,000 chickens inside a crowded coop, a deadly bird-flu epidemic would probably have resulted, wiping out all the chickens, as well as many villagers. No priest, shaman or witch doctor could have prevented it. But once modern science had deciphered the secrets of birds, viruses and antibiotics, humans could begin to subject animals to extreme living conditions. With the help of vaccinations, medications, hormones, pesticides, central air-conditioning systems and automatic feeders, it is now possible to cram tens of thousands of chickens into tiny coops, and produce meat and eggs with unprecedented efficiency.
The fate of animals in such industrial installations has become one of the most pressing ethical issues of our time, certainly in terms of the numbers involved. These days, most big animals live on industrial farms. We imagine that our planet is populated by lions, elephants, whales and penguins. That may be true of the National Geographic channel, Disney movies and children’s fairytales, but it is no longer true of the real world. The world contains 40,000 lions but, by way of contrast, there are around 1 billion domesticated pigs; 500,000 elephants and 1.5 billion domesticated cows; 50 million penguins and 20 billion chickens. [Continue reading…]
Imagining strange new lifeforms could help us discover our own origins
By Michael Page, University of Huddersfield
From the earliest of times, philosophers and scientists have tried to understand the relationship between animate and inanimate matter. But the origin of life remains one of the major scientific riddles to be solved.
The building blocks of life as we know it essentially consist of four groups of chemicals: proteins, nucleic acids, lipids (fats) and carbohydrates. There was much excitement about the possibility of finding amino acids (the ingredients for proteins) on comets or distant planets because some scientists believe that life on Earth, or at least its building blocks, may have originally come from outer space and been deposited by meteorites.
But there are now extensive examples of how natural processes on Earth can convert simple molecules into these building blocks. Scientists have demonstrated in the lab how to make amino acids, simple sugars, lipids and even nucleotides – the basic units of DNA – from very simple chemicals, under conditions that could have existed on early earth. What still eludes them is the point in the process when a chemical stew becomes an organism. How did the first lifeforms become alive?
Paleogenetics is helping to solve the great mystery of prehistory: How did humans spread out over the earth?
Jacob Mikanowski writes: Most of human history is prehistory. Of the 200,000 or more years that humans have spent on Earth, only a tiny fraction have been recorded in writing. Even in our own little sliver of geologic time, the 12,000 years of the Holocene, whose warm weather and relatively stable climate incubated the birth of agriculture, cities, states, and most of the other hallmarks of civilisation, writing has been more the exception than the rule.
Professional historians can’t help but pity their colleagues on the prehistoric side of the fence. Historians are accustomed to drawing on vast archives, but archaeologists must assemble and interpret stories from scant material remains. In the annals of prehistory, cultures are designated according to modes of burial such as ‘Single Grave’, or after styles of arrowhead, such as ‘Western Stemmed Point’. Whole peoples are reduced to styles of pottery, such as Pitted Ware, Corded Ware or Funnel Beaker, all of them spread across the map in confusing, amoeba-like blobs.
In recent years, archaeologists have become reluctant to infer too much from assemblages of ceramics, weapons and grave goods. For at least a generation, they have been drilled on the mantra that ‘pots are not people’. Material culture is not a proxy for identity. Artefacts recovered from a dig can provide a wealth of information about a people’s mode of subsistence, funeral rites and trade contacts, but they are not a reliable guide to their language or ethnicity – or their patterns of migration.
Before the Second World War, prehistory was seen as a series of invasions, with proto-Celts and Indo-Aryans swooping down on unsuspecting swaths of Europe and Asia like so many Vikings, while megalith builders wandered between continents in indecisive meanders. After the Second World War, this view was replaced by the processual school, which attributed cultural changes to internal adaptations. Ideas and technologies might travel, but people by and large stayed put. Today, however, migration is making a comeback.
Much of this shift has to do with the introduction of powerful new techniques for studying ancient DNA. The past five years have seen a revolution in the availability and scope of genetic testing that can be performed on prehistoric human and animal remains. Ancient DNA is tricky to work with. Usually it’s degraded, chemically altered and cut into millions of short fragments. But recent advances in sequencing technology have made it possible to sequence whole genomes from samples reaching back thousands, and tens of thousands, of years. Whole-genome sequencing yields orders of magnitude more data than organelle-based testing, and allows geneticists to make detailed comparisons between individuals and populations. Those comparisons are now illuminating new branches of the human family tree. [Continue reading…]
The politics of human evolution
Candida Moss writes: On Thursday morning The New York Times ran a high profile story about the discovery of a new human ancestor species — Homo naledi — in the Rising Star cave in South Africa. The discovery, announced by professor Lee Berger, was monumental because the evidence for Homo naledi were discovered in a burial chamber. Concern for burial is usually seen as distinctive characteristic of humankind, so the possibility that this new non-human hominid species was ”deliberately disposing of its dead” was especially exciting.
To anthropologists the article was not only newsworthy it was also humorous, for the Times illustrated the piece with a photograph of Australopithecus africanus, a species already well-known. This howler of a mistake (at least to self-identified science nerds) was also somewhat understandable because the differences between the two skulls are sufficiently subtle that a lay viewer can indeed easily mistake them for one another. In fact, some have pointed to that similarity and wondered (while acknowledging the importance of the discovery) if it is indeed a “new species.”And that gets to the deeper issue: What and who were our ancestors?
It might seem as if the answer to this question is simply a question of biology, but in his new book Tales of the Ex-Apes: How we think about human evolution anthropologist Jonathan Marks argues that the story we tell about our origins, the study of our evolutionary tree, has cultural roots. Evolution isn’t just a question of biology, he argues, it’s also a question of mythology. Our scientific facts, he says, are the product of bioculture and biopolitics. [Continue reading…]
Guns, germs, and steal
We have all been raised to believe that civilization is, in large part, sustained by law and order. Without complex social institutions and some form of governance, we would be at the mercy of the law of the jungle — so the argument goes.
But there is a basic flaw in this Hobbesian view of a collective human need to tame the savagery in our nature.
For human beings to be vulnerable to the selfish drives of those around them, they generally need to possess things that are worth stealing. For things to be worth stealing, they must have durable value. People who own nothing, have little need to worry about thieves.
While Jared Diamond has argued that civilization arose in regions where agrarian societies could accumulate food surpluses, new research suggests that the value of cereal crops did not derive simply from the fact that the could be stored, but rather from the fact that having been stored they could subsequently be stolen or confiscated.
Joram Mayshar, Omer Moav, Zvika Neeman, and Luigi Pascali write: In a recent paper (Mayshar et al. 2015), we contend that fiscal capacity and viable state institutions are conditioned to a major extent by geography. Thus, like Diamond, we argue that geography matters a great deal. But in contrast to Diamond, and against conventional opinion, we contend that it is not high farming productivity and the availability of food surplus that accounts for the economic success of Eurasia.
- We propose an alternative mechanism by which environmental factors imply the appropriability of crops and thereby the emergence of complex social institutions.
To understand why surplus is neither necessary nor sufficient for the emergence of hierarchy, consider a hypothetical community of farmers who cultivate cassava (a major source of calories in sub-Saharan Africa, and the main crop cultivated in Nigeria), and assume that the annual output is well above subsistence. Cassava is a perennial root that is highly perishable upon harvest. Since this crop rots shortly after harvest, it isn’t stored and it is thus difficult to steal or confiscate. As a result, the assumed available surplus would not facilitate the emergence of a non-food producing elite, and may be expected to lead to a population increase.
Consider now another hypothetical farming community that grows a cereal grain – such as wheat, rice or maize – yet with an annual produce that just meets each family’s subsistence needs, without any surplus. Since the grain has to be harvested within a short period and then stored until the next harvest, a visiting robber or tax collector could readily confiscate part of the stored produce. Such ongoing confiscation may be expected to lead to a downward adjustment in population density, but it will nevertheless facilitate the emergence of non-producing elite, even though there was no surplus.
This simple scenario shows that surplus isn’t a precondition for taxation. It also illustrates our alternative theory that the transition to agriculture enabled hierarchy to emerge only where the cultivated crops were vulnerable to appropriation.
- In particular, we contend that the Neolithic emergence of fiscal capacity and hierarchy was conditioned on the cultivation of appropriable cereals as the staple crops, in contrast to less appropriable staples such as roots and tubers.
According to this theory, complex hierarchy did not emerge among hunter-gatherers because hunter-gatherers essentially live from hand-to-mouth, with little that can be expropriated from them to feed a would-be elite. [Continue reading…]